Smith P A, Lutman M E
MRC Institute of Hearing Research, General Hospital, Nottingham, UK.
Br J Audiol. 1992 Feb;26(1):59-61. doi: 10.3109/03005369209077872.
The issue of BS 2497 Parts 5 and 6 in 1988 brought British Standards into line with the latest revisions to ISO 389. As a consequence, many audiometers that were previously calibrated using a 9-A coupler will now have to be calibrated with an artificial ear. Whilst this may appear to be a seemless change involving merely alterations to measurement apparatus, this technical note illustrates for two earphone types that it entails a shift in the Hearing Level standard by a maximum of 3 dB at 2 kHz. This has ramifications for longitudinal studies of hearing and for monitoring of hearing threshold levels in persons exposed to noise.
1988年英国标准2497第5部分和第6部分的问题使英国标准与ISO 389的最新修订保持一致。因此，许多以前使用9-A耦合器校准的听力计现在必须使用人工耳进行校准。虽然这似乎是一个无缝的变化，仅仅涉及测量设备的改变，但本技术说明表明，对于两种耳机类型，这将导致听力级标准在2 kHz时最多偏移3 dB。这对听力的纵向研究以及对接触噪声人员的听力阈值水平监测都有影响。
